Popriv

Pulling my high wing trainer out of mothballs. It's a sky raider, made by world models ( I think?)
I have an OS .46 max fx that I just ordered from eBay. ( we will see what/if it shows up?)

Will I have any problems making this a tail dragger? We have a somewhat rough grass field and I'm tired of the bent nose gear.
How would I determine the best position to mount the gear?

Thanks

JeffinTD

I banged up the nose wheel on my trainer until I got the hang of flaring to land on the mains.

Anyway, you would want the mains a few inches forward of the CG. Not familiar with that model, but I would assume you would have to strengthen the fuse to mount the mains, and the tail wheel.

I converted an Advance to tail dragger. I cut out the balsa sheeting under part of the fuse and replaced with plywood, and added some gussets inside to the sides, along with some balsa to tie the main gear mount area to the battery tray. You may have a servo tray you could tie things into?

Dubro makes some nice tail wheel brackets that work well for conversions.

grosbeak

I turned my Hobbistar 60 into a tail dragger over the winter. Here's a link to the write up:

http://www.grosbeakrc.ca/hangar/hobb...ildragger.html

mike109

G'day. The old rule of thumb for the main wheel's position is that they should be set up so that about 1/3 or a little more of the wheel is in front of the leading edge of the wing. If it is too far forward, the model will tend to bounce on landing and if it is too far back, it will tend to nose over both on landing and when you are trying to taxi and take off. The safest is to be a bit too far forward.

Cheers

Mike in Oz

flyinwalenda

My Feedback: (5)

As mentioned located the mains a  bit in front of the CG.  I wouldn't re-use the stock mains but rather look for a lightweight set of main gear something like this: http://www3.towerhobbies.com/cgi-bin...?&I=LXNM65&P=6     The fuselage looks to be made out of heavier balsa sheet so you may be alright with installing/gluing  a plywood block on the inside bottom . Use some blind nuts and blots to attach the mains.
For the tail wheel you could use something like this: http://www3.towerhobbies.com/cgi-bin...?&I=LXD850&P=7

JohnBuckner

My Feedback: (1)

With a taildragger the fore and aft positioning is critical and Mike109 is right on when to far forward the airplane will become what I call a boinger during a landings .. The perfect placement in terms of easy to land is eactly at the CG. I actually have flown some early full scale gliders like that and what butter cups they were. Virtually all modern full scale gliders are now taildraggers. This of couse presents us with the problem of keeping the propellor off the ground so its necessary to put it forward a bit as Mike suggested with the wheels center footprint somewhere around the leading edge of the wing.

It can be to your advantage if you use a bolted gear to actually use several bolt holes on the gear plate to have several sets of hole about a quarterinch apart for some adjustment. There is a another way to make fore and aft adjustment at the axles that I will show a picture of later after my trip to the field if any interest.

John

JeffinTD

This was the tail assembly type I meant.

http://www3.towerhobbies.com/cgi-bin...P?I=LXFV47&P=8

For mains, I made mine out of music wire. I curled the end of a small metal bracket and soldered it to the wire to accept nylon bolts to mount it.

It worked out very well, as the music wire has just enough spring to it to protect the airframe from the jolt of a poor landing.

Popriv

Thanks for the tips!
I already reinforced the bottom of the fuse as I have this plane set up for floats. I just have to add some blind nuts in the correct position to bolt on landing gear.

Also, the used engine from eBay showed up today. Very fast delivery and it looks good. We just have to see how it starts and runs...


Steve

HighPlains

My Feedback: (1)

The location of wheels for conventional geared model aircraft should be in line with the actual CG, and swept forward 15 to 18 degrees, depending on the surface that you fly from. Off of smooth pavement, 15 degrees works well, but on grass you want about 18 degrees. The length of the struts need to maintain prop clearance with the tail slightly above a flying angle of attack, unless you want to always do three point take-offs and landing (hard to do). If the gear are too long, you end up with too much angle of attack for the wing, which makes take-offs more difficult, so having a longer strut on the tailwheel helps make ground operations easier.

The CG is not where an airplane balances on the wing. It is the actual location where if the airplane is suspended from any point, the CG is directly below the string. Done from multiple locations, you soon find out where the actual CG is. Of course, after you hang on the landing gear and wheels, the CG will be shifted.